Solar Terrestrial Activity Report [Image] Last update October 28, 2002 at 02:50 UTC. [Solar and geomagnetic data - last 4 weeks (updated daily)] [Solar wind and electron fluence charts (updated daily)] [Solar cycles 21-23 (last update October 2, 2002)] [Solar cycles 1-20] [Graphical comparison of cycles 21, 22 and 23 (last update October, 2002)] [Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update October 2, 2002)] [Historical solar and geomagnetic data charts 1954-2002 (last update October 13, 2002)] Recent activity The geomagnetic field was quiet to active on October 27. Solar wind speed ranged between 497 and 682 km/sec under the influence of a high speed coronal stream. Solar flare activity was low. Solar flux was 157.1, the planetary A index was 22 (STAR Ap - based on the mean of three hour ap indices: 23.0). Three hour interval K indices: 24434444 (planetary), 23423434 (Boulder). The background x-ray flux is at the class B6 level. At midnight there were 9 spotted regions on the visible disk, 2 of which have not yet been numbered. A total of 10 C class events were recorded during the day. A C4.0 event at 22:03 UTC had its origin in spotless plage at N18E62. Region 10162 decayed further in the southern and central section of the trailing spots, while development continued in the northern section. A magnetic delta structure formed again in this developing area. M class flares are possible. Flares: C1.6 at 03:54, C1.3 at 06:56, C1.2 at at 08:20, C1.3 at 09:21, C1.6 at 10:11, C1.9 at 17:58 and C2.9 at 20:38 UTC. Region 10165 decayed slowly and quietly. Region 10167 was quiet and stable. Region 10169 was quiet and stable. A new spot formed in the southwestern section of the region. It is currently uncertain if this new spot actually belongs to this region or is a separate region. Region 10170 was quiet and stable. Region 10171 was quiet and stable. New region 10172 rotated into view at the southeast limb early on October 26 and was numbered on Oct.27. No changes were observed during the day. Spotted regions not yet numbered: [S11] A new region emerged in the southwest quadrant on Oct.27. Location at midnight: S15W55. [S12] A new region emerged in the southwest quadrant late on Oct.27. Location at midnight: S12W30. Coronal mass ejections (CMEs) October 25: A full halo CME was observed in LASCO C3 images beginning at 10:42 UTC. The source of this CME was likely the same as that of the two halo CMEs observed on October 24. It should be noted that there was a large eruption in the southeast quadrant shortly before the observation of this CME. Material from this eruption was observed along the southeastern front of the full halo CME and there is a possibility that some if this material could reach Earth on October 27 or 28. Another full halo CME was observed beginning at 15:42 UTC in LASCO C3 images. The source was likely from the same region that had produced 3 other full halo CMEs on Oct.24-25. A CME was observed above the north pole and the northwest limb starting at 18:42 UTC and was associated with the M1 event in region 10162. This CME does not appear to have any geoeffective components. October 26: Another full halo CME was observed after 08h UTC. The source of this CME is likely the same southern hemisphere region being the source of the 4 full halo CMEs observed on October 24-25. Interestingly, SOHO MDI far side images reveal a large region in the same position as would be expected from the material distribution observed during all the halo CMEs. Further large CMEs could be observed before the region rotates into view on November 1-2. October 27: No CMEs of interest were observed until late in the day. A C4.0 event in the northeast quadrant was associated with a CME off the east limb. The CME was first visible in LASCO C2 images at 22:26 UTC. A full halo CME was visible by midnight, this CME was observed with most of the material over the southeast quadrant and may have the same source (a large region several days behind the southeast limb) as numerous halo CMEs observed October 24-26. Coronal holes A trans equatorial coronal hole will rotate into a geoeffective position on November 1-2. Forecast The geomagnetic field is expected to be quiet to active on October 28-29. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor. Coronal holes (1) Coronal mass M and X class flares (3) ejections (2) [Coronal hole indicator][CME indicator] [M and X class flare indicator] 1) Effects from a coronal hole could reach Earth within the next 5 days. 2) Material from a CME is likely to impact Earth within 96 hours. 3) There is a possibility of either M or X class flares within the next 48 hours. Green: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% probability. Active solar regions (Recent map) Data for all numbered solar regions according to the Solar Region Summary provided by SEC/NOAA. Comments are my own, as is the STAR spot count (spots observed at or just prior to midnight) and data for regions not numbered by SEC or where SEC has observed no spots. Solar Date SEC STAR Location region numbered spot spot at AreaClassification Comment countcount midnight 10162 2002.10.17 39 33 N26W43 0680 FKC beta-gamma-delta 10164 2002.10.20 N11W39 plage 10165 2002.10.20 4 2 N21W22 0150 CAO classification should be HAX 10166 2002.10.23 S06W44 plage 10167 2002.10.23 1 3 N18E24 0020 HSX area was 0050 at midnight 10169 2002.10.24 2 4 S18E33 0050 DSO 10170 2002.10.25 2 2 S12E38 0030 CSO 10171 2002.10.25 1 1 N11E52 0060 HSX 10172 2002.10.27 1 1 S16E56 0030 HSX formerly region S09 S10 emerged on N08E21 plage 2002.10.26 S11 emerged on 2 S15W55 0010 BXO 2002.10.27 S12 emerged on 2 S12W30 0010 BXO 2002.10.27 Total spot count: 50 50 SSN: 120 140 Monthly solar data Average Month solar International sunspot Smoothed sunspot flux at number number Earth 2000.04 184.2 125.5 120.8 cycle 23 sunspot max. 2000.07 202.3 170.1 119.8 2001.09 233.2 150.7 114.1 (+0.5) 2001.10 207.6 125.5 114.0 (-0.1) 2001.11 210.6 106.5 115.5 (+1.5) 2001.12 235.1 132.2 114.6 (-0.9) 2002.01 226.6 114.1 113.5 (-1.1) 2002.02 205.0 107.4 114.7 (+1.2) 2002.03 179.5 98.4 113.4 (-1.3) 2002.04 189.8 120.7 (109.7 predicted, -3.7) 2002.05 178.4 120.8 (105.9 predicted, -3.8) 2002.06 148.7 88.3 (101.4 predicted, -4.5) 2002.07 173.5 99.9 (96.5 predicted, -4.9) 2002.08 183.6 116.4 (92.5 predicted, -4.0) 2002.09 175.8 109.3 (88.7 predicted, -3.8) 2002.10 167.4 (1) 133.6 (2) (84.6 predicted, -4.1) 1) Running average based on the daily 20:00 UT observed solar flux value at 2800 MHz. 2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number is typically 25-45% less. This report has been prepared by Jan Alvestad. It is based partly on my own observations and interpretations, and partly on data from sources noted in solar links. Comments and suggestions are always welcome. ------------------------------------------------------------------------ [DX-Listeners' Club] [DX News]